Vernier divider or caliper



Nov. 29,1927.: 1,650,704 Y L g V. H.GA A yERNIERjDIvIDER 'on GALIPERFiled April 22. -1925 Patented Nov. 29, 1927.

narran STATES 'VICTOR H. GAA, OF DETROIT, MICHIGAN.

VERNIEB DIVIDR 0B CALIPEB. 1

Application` llled April 2,2, 1926. -Serial No. 104,031.

My invention relates to dividing and caliering instruments, and in itsgeneral ob- ]ects includes the providing of an instru-- arms constructedso'that they will permit an easy regrinding of their tips withoutaffect'- ing the accuracy of the readings, and aims' to provide simpleand effective means for maintaining the divider arms accuratelypositioned with respect to the indicating portions ofthe instrument.v

Illustrative of my invention, Fig. l is a fragmentary side elevation ofa combined Vernier caliper and Vernier divider embodying the same. u

Fig. 2 is a horizontal section taken along the line 22 of Fig. 1.- l

Fig. 3 is a fragmentary vertical sectio taken through the sameinstrument along the line 3-3 of F ig. 2.

Fig. 4 is a side elevation of one of the de- A tachable divider arms.

v Fig. 5 is an enlarged and fragmentary vertical section taken along theline 5-5 of Fi 1.

the illustratedv embodiment my combination Vernier instrument includes astandard type of Vernier caliper designed for accurate inside measuringby having a Vernier scale arrangement graduated to indicate the distancebetween the oppositely directed parallel edges of the tips 1A and 2A ontwo main jaw portions 1 and 2, both of which extend at right anglestothe main bar 3 ofthe instrument. The main jaw portion 1 is integralwith this main bar, while the companion main jaw portion 2 is fast upona slide 4 through which the main bar 3 slid.-

ably extends, and this slide has a threaded,

stem 5 projecting from it parallel to the bar 3. Threaded on this stem 5is anut 6 whichY fits closely between the forks 7A of an auxiliary slide7 through which the main bar 3 also extends, this auxiliary slide havinga screw 8 threaded through it and adapted to engage the mainbar so as toclamp the slide to the bar. v

The main bar 3 has an indicating scale 9 at one of its'longitudinaledges, and the slide 4 carries a Vernier scale 10 adjacent to the saidscale 9 to permit an accuratereading of the said spacing between theedges lA and 2A of the jaw tip portions. The main slide 4 also hasl ascrew 11 extending through it and`- adapted to clam the main slide onthe bar 3 after thissli e has been accurately adjusted in .position bymanipulating the nut 6.

lTo adapt sucha Vernier caliper `for use as an equally accurate dividinginstrument, I provide two divider attachments respectively adapted to beattached to the arms land 2 of the caliper. Each of these attachmentshas an upper portion 12 of approximately V-shape, with the bore of thatportion closely fitting one of the said arms, and also hasan integrallower part in the form of a slenderr divider arm 13.

The opposed faces 13A and 13B of these divider arms are in planes atright angles to the indication-carrying face of the main arm 3 of theinstrument and are accurately spaced from each other by the samedistance as that vbetween the oppositely directed faces 1A and 2A of thecaliper arm tips. Hence the same indicating reading which is accuratefor the jaw tip portions when the instrument is used forv measuring thediameter" of a bore (or for any other inside measurement) is equallyaccurate for indicating the spacing of these faces 1A and 2A. To utilizethis arrangement, I grind the divider arms Vfrom their oppositelydirected faces, thereby providing divider points in the said planes ofthe inner faces 13A and 13B of the divider arms.

For securing the detachable arms to the caliper arms, I preferablyprovide each detachable arm with a screw 14 having a tapering shankportion 14A accurately itting the taper of a bore in one side of thechanvider arm and having its free shank end 14B threaded into the otherside of the same channel-sectioned portion, the screw having itsintermediate portion passing through a perforatioir in thecorrespondi'ngvcaliper arm (l or 2), as shown in Fig. 5. ith the partsthus arranged, the conforming of the bore of the upper divider armportion to the shape of the corresponding caliper arm portion guides thedivider arm to its proper position when itis being attached, after whlcha tightening of the screw 14 springs the wings of the channeled dividerarm portion l2 toward each other so as to clamp the interposed caliperarm part tightly between these Wings. To increase the accuracy of thisguiding and alining of the divider 'arms with respect tothe caliperarms, I preferably provide these with auxiliary alining means,

such assteel pins 16 fastened respectively to the divider arms andextending parallel to the faces l3^ and each entering a correspondingbore in one of the caliper arm tips,

as shown in Fig. 3.

With divider attachments thus constructed, the spacing between thedivider points can easily be read-or predeterminedwith the same highdegree of accuracy as that ofthe usual caliper arm edges. And, sincethese spacings are identical, no calculations or allowances forvariations in them are needed. Moreover, when the divider points getdull, I can still maintain this same accuracy by regrindinv them so asto have the tips in the planes o? the inner faces (13A and 13B) vand soas to leave the divider arms of equal length. Hence my above describedattachments provide a simple means for converting a standard verniercaliper into an equally convenient divider which can readily be adjustedwith the same degree of accuracy and in which the adjusted spacing caninstantly be read on the Vernier scale. Since this direct-readingfeature eliminates the need of applying the divider points to a scalefor determining their distance, much time is saved in reading the theactual spacing. And, since the threaded connection between the twoslides permitsof a very delicate adjustment of the divider pointspacing, I can secure a much greater accuracy of this adjustment than ispossible with ordinary` dividers.

Moreover, by making such divider arms detachable and by using a scalearrangement corresponding in indications to the spacing between twocaliper arm edges, I-provide a combination instrument which is equallysuitable`for accurate use in so-called inside calipering.

` embodiment, I do notrwish to be limited to the details of theconstruction and arrangement thus disclosed, -since changes might ntions of the said jaws an obviously be made without departing eitherfrom the spirit of my invention or from the appended claims.

I claim as my invention:

l. The combination with an inside caliper for inside measurements havinga pair of relatively slidable single-jawed members provided withco-operating markings for indicating the spacing between the oppositelyfacing edges of the jaws of the two members, of a pair of pointedauxiliary members respectively detachably sleeved upon the said jaws andhaving their points spaced to aline respectively with the said jawedges.

2. In combination, a caliper for inside measurements having a pair ofrelatively slidable members each provided with a jaw having a tipextending at right angles to the direction in which the members arerelatively slidable, the said jaws having parallel outer edges and thesaid members have adjacent markings for indicating the spacing of theouter edges, the said jaw tips projecting for the same distance beyond.'the free ends of the jaws; and a pair of divider attachments of equallength each having one end pointed and having its other end portionsleeved upon the free end of one jaw and abutting against the end of thetip on that jaw, the said attachments having their pointed endsrespectively in alinement with the said outer jaw edges.

3. A caliper and divider attachment combination as per claim 2, in whichthe said attachments have opposed faces respectively alining with thesaid outer jaw edges.

4. A combined caliper and scribing device comprising a bar, a slidemovable upon the bar, two jaws having their main ortions respectivelyfast upon the bar and t ie slide and extending in the same direction atright angles to the slide, the jaws also having tip portions presentingoppositely directed edges at right angles to the slide, the bar and theslide being provided with co-operating markings for indicatin thespacing between the said oppositely facing edges; and a pair of pointedauxiliary members detachably sleeved respectively u on the mainporlaterally spaced from the said tip portions, the said members havingpoints projecting beyond the said tip portions and spaced to alinerespectively with the said edges of the j aw tip portions.

5. A combined caliperand scribing device as per claim 4, in which theauxiliary members have opposed faces at right angles to the slide and inalinement with the points of the said members, thereby permitting freshpoints to be ground upon the said members without alterin the accuracyof the indications afforded y the said co-operating markings.

6. In combination: an inside caliper having two jaws each provided witha tip, the

two jaw tips extending alongside each other and having their oppositelyfacing objectengaging edges parallel; a pair of attachments respectivelysleeved upon the two jaws and having opposed edges respectively aliningwith the said o positely facing edges of the two jaws; each Ija'w havinga bore ex-

